Diagnosis of Filariasis is confirmed most commonly done by

Standard/definitive method for diagnosing active Filariasis infection is the identification of microfilariae in a blood smear by microscopic examination. Microfilariae that cause Lymphatic Filariasis circulate in the blood at night (Nocturnal periodicity) Blood collection (20 cu.mm) should be done at night to coincide with the appearance of the microfilariae, and a thick smear should be made and stained with Giemsa or haemayoxylin and eosin For increased sensitivity, concentration techniques can be used Serological techniques provide an alternative to microscopic detection of microfilariae for the diagnosis of Lymphatic Filariasis Patients with active filarial infection typically have elevated levels of antifilarial IgG4 in the blood and these can be detected using routine assays Ref: Park 25th edition Pgno : 298